Index: wp-admin/includes/ajax-actions.php
===================================================================
--- wp-admin/includes/ajax-actions.php	(revision 24203)
+++ wp-admin/includes/ajax-actions.php	(working copy)
@@ -1352,6 +1352,12 @@ function wp_ajax_inline_save() {
 	if ( empty($data['ping_status']) )
 		$data['ping_status'] = 'closed';
 
+	// Hack: wp_unique_post_slug() doesn't work for drafts, so we will fake that our post is published.
+	if ( ! empty( $data['post_name'] ) && in_array( $post['post_status'], array( 'draft', 'pending' ) ) ) {
+		$post['post_status'] = 'publish';
+		$data['post_name'] = wp_unique_post_slug( $data['post_name'], $post['ID'], $post['post_status'], $post['post_type'], $post['post_parent'] );
+	}
+
 	// update the post
 	edit_post();
 
Index: wp-admin/includes/post.php
===================================================================
--- wp-admin/includes/post.php	(revision 24203)
+++ wp-admin/includes/post.php	(working copy)
@@ -995,9 +995,8 @@ function get_sample_permalink($id, $title = null, $name = null) {
 	$original_date = $post->post_date;
 	$original_name = $post->post_name;
 
-	// Hack: get_permalink would return ugly permalink for
-	// drafts, so we will fake, that our post is published
-	if ( in_array($post->post_status, array('draft', 'pending')) ) {
+	// Hack: get_permalink() would return ugly permalink for drafts, so we will fake that our post is published.
+	if ( in_array( $post->post_status, array( 'draft', 'pending' ) ) ) {
 		$post->post_status = 'publish';
 		$post->post_name = sanitize_title($post->post_name ? $post->post_name : $post->post_title, $post->ID);
 	}